CVE-2026-26991 MEDIUM

CVE-2026-26991: LibreNMS vulnerable to Stored Cross-site Scripting through unsanitized /device-groups name

Vendor Librenms
Product librenms
Weakness CWE-79 · XSS
Published February 20, 2026
Last update February 20, 2026

CVSS base score

5.1/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N

What the vulnerability does

01Description

LibreNMS is an auto-discovering PHP/MySQL/SNMP based network monitoring tool. In versions 26.1.1 and below, the device group name is not sanitized, allowing attackers with admin privileges to perform Stored Cross-Site Scripting (XSS) attacks. When a user adds a device group, an HTTP POST request is sent to the Request-URI "/device-groups". The name of the newly created device group is stored in the value of the name parameter. After the device group is created, the entry is displayed along with relevant buttons such as Rediscover Devices, Edit, and Delete. This issue has been fixed in version 26.2.0.

Key dates

02Disclosure timeline

February 20, 2026 CVE published
February 20, 2026 Record updated